US 2006/0221012 A1Published application

Display device and method for driving display device

AssigneeSanyo Electric Co., Ltd.

InventorKyoji Ikeda

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Abstract

An element driving transistor controls an amount of power supplied from a power supply PVDD to an element to be driven (display element) provided in a pixel of each row. A storage capacitor has a first electrode connected to a gate electrode of an element driving transistor and a second electrode connected to a capacitor line. A voltage level of a capacitor control signal SCn to be output to the capacitor line is set to a voltage level which controls the element driving transistor via the storage capacitor Cs to be periodically switched off. A V driver formed at a periphery of a display portion of a panel has a generator which generates a capacitor control signal SCn using outputs of registers which sequentially transfer and output a signal according to a V start signal STV so that the off-control period of the element driving transistor is determined according to the H level period of the V start signal STV. The voltage level of the capacitor control signal allows, for each row, the element driving transistor to be controlled to be switched off for a period according to the signal STV and persistent images can be improved.

Claims12

Dependent claims

A display device having a plurality of pixels arranged in a matrix and a vertical driver which sequentially drives the plurality of pixels, wherein

each of the plurality of pixel comprises:
an element to be driven;
a selection transistor which reads a data signal from a data line extending along a vertical scan direction according to a selection signal output on a selection line extending along a horizontal scan direction;
a storage capacitor having a first electrode and a second electrode and which stores, as a voltage with respect to a voltage supplied from a capacitor line to the second electrode, a data signal from the selection transistor supplied to the first electrode;
and
an element driving transistor having a gate connected to the first electrode of the storage capacitor and which supplies power corresponding to a data voltage stored in the storage capacitor from a power supply to the element to be driven,
a plurality of the selection lines are provided, each of which extends along the horizontal scan direction,
the vertical driver comprises a vertical transfer register having a plurality of stages of registers which sequentially read and transfer a vertical start signal indicating a start timing of one vertical scan period, a selection signal generator which generates the selection signal to be supplied to the selection line, and a capacitor control signal generator which generates a capacitor control signal to be supplied to the capacitor line,
the selection signal generator generates, based on the vertical start signal, the selection signals at timings which differ from each other by one horizontal scan period to be sequentially supplied to the selection lines,
the capacitor control signal generator generates the capacitor control signal based on an output, corresponding to the vertical start signal, from the register of each stage of the vertical transfer register, and
the capacitor control signal has a first voltage level state which causes the storage capacitor to store the voltage corresponding to the data signal via the capacitor line and causes the element driving transistor to operate according to the stored voltage and a second voltage level state which causes a corresponding element driving transistor to be controlled to be switched off.

8 more elements

A method of driving a display device comprising a plurality of pixels arranged in a matrix of n rows and m columns, wherein a selection line and a capacitor line are formed for each row along a horizontal scan direction, a data line is formed for each column along a vertical scan direction, each of the plurality of pixels comprises an element to be driven, a selection transistor having a gate connected to the selection line and a first conductive region connected to the data line and which reads a data signal from the data line according to a selection signal output to the selection line, an element driving transistor having a gate connected to a second conductive region of the selection transistor and which controls power to be supplied from a power supply to the element to be driven, and a storage capacitor having a first electrode and a second electrode, wherein the first electrode is connected to the second conductive region of the selection transistor and the gate of the element driving transistor, the second electrode is connected to the capacitor line, and a data signal supplied via the selection transistor to the first electrode is stored in the storage capacitor as a potential difference with respect to a capacitor control signal supplied from the capacitor line to the second electrode, wherein

a selection signal is output to the selection line of an nth row to control the selection transistors of pixels of the nth row to be switched on and write a voltage corresponding to a data signal to the storage capacitor, and a potential of the capacitor control signal to be output to the capacitor line of the nth row is set to a first voltage level which causes the element driving transistor to be switched on and operate according to a data signal supplied via the selection transistor, and
after the first voltage level is maintained for a period corresponding to a duration of a start instruction level of a vertical start signal indicating a start timing of one vertical scan period, the potential of the capacitor control signal is changed to a second voltage level which controls, via the capacitor line, the element driving transistor to be switched off for a period in which the selection line of the nth row is not selected and until a start of a next vertical scan period so that the element driving transistor and the element to be driven are controlled to be switched off.

Dependencies are inferred from the claim text.

Facts

Application: 11/395,904Filed 31 Mar 2006
Priority: JP 2005-10318131 Mar 2005
Published: 5 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G09G 3/3233
Using an active matrix: with pixel circuitry controlling the current through the light-emitting element
G09G 3/3266
Organic, e.g. using organic light-emitting diodes [OLED]: details of drivers for scan electrodes
G09G 2300/0417
Matrix technologies: special arrangements specific to the use of low carrier mobility technology
G09G 2300/0842
Several active elements per pixel in active matrix panels: forming a memory circuit, e.g. a dynamic memory with one capacitor